That's the thing, they make the base game really bland. For example religions and cultures are almost exactly the same, there are no proper mechanisms for Crusades and Jihads, just one type of government...
Everything else got added via DLCs.
Besides, even though you do not NEED DLCs, the way the company tries to prey on FOMO of (potential) customers is disgusting to say the least. I expect Black Sea Games and THQ Nordic to be much better in this regard, they have no track record of releasing an endless wave of DLCs.